Steam heating system



June 19, 1928.

H. E. LA BOUR STEAM HEATING SYSTEM Filed Feb. 25, 1924 4 S11eets-Sheet 5 PUMP mscnmzse 62 (awn 655a? Patented June 19, 1928.

UNITED .STA

H ARRY E. LA BOUR, OF HOMEWOOD, ILLINOIS.

STEAM HEATING SYSTEM.

Application filed February 23, 1924. Serial Ho. 694,526.

My invention relates to str u'n heating systems, and more particularly to the pumping and control mechanisms for maintaining'a vacuum upon the radiators aridfor 6 returning the water to the boiler.

As is well known to those skilled in the art, steam heating systems are now commonly in use employing steam at a relatively low boiler pressure and employing a vacuum I circulating pump for maintaining a circulation through the radiators and for withdrawing the condensate and waste steam mixed with air which leaks into the system. It is desirable to separate out the air, condense the steam and return the condensate to the boiler, either directly or indirectly. It will be seen that there are a number of functions involved in this relatively complex problem. First, there is the necessity fol-maintaining avacuum upon the return line, and this vacuum must be maintained without discharging all of the'gaseous fluid to' atmosphere, because the gaseous fluid which comes from the return line contains 26 a large proportion of steam which is flashed to a vapor because of the reduced pressure.

It has generally been found advisable to compress this gaseous fluid in order to condense the water vapor and separate the air 30 or other gases from the water and discharge the gases to atmosphere and return the con-' densate which is thus roduced to the boiler.

' If all of the fluid or the return line werein gaseous or vapor condition, then a relatively small high speed positive displacement pump, in the nature= of a compressor, might be desirable, but the problem is complicated by the fact that liquid is also drawn from the return pipe,

40 and hence any positive displacement pump ,would have to" operate at a ispeed suitable for handling liquid. 'This' -would'require a relatively large slow speed pump not partic-- ularly suited to present'day conditions. It 15 is desirable to employ an electricmotor for work of this character, and ."this means a motor speed of approximately eighteen hundred (18 00) revo utions per minute, hence a positive displacement pump is not satisfactory.

The art has developed into the use of umps not of the positive displacmentftype,

use 'of compactness relative uids which came from.

.. pump or a the vacuum in the return line of the steam' heating system and to return the condensate t0 the boiler. been successfully developed according to two methods. 7

According to the first method, all of the condensate, flash steam and noncondensable gases are returned to a tank or receiver which is kept under the vacuum of the system. Here the gases and vapors separate from the water,and the accumulated water is drawn oil and returned to the boiler by a Water pump "which is usually of the centrifugal type. The gases are removed from the top of the receiver by a separate air or vapor pump and are discharged to atmos phere. Both pumps may be driven by one electric motor, or individual drive may be provided. The N ash or Jennings? system is typical'of this mode of operation.v

Such system is eflective in operation, but requires an unnecessary complication. of

Heretoiore, the art. has

running parts and incorporates the inefliciency of two (pumps. In addition, the gaseous fluid is lschal ged into the atmosphere containing a considerable content of I flash Steam.

The second mode of operation employs one or two pumps, either or both of which. always handle water only. 5 Water is drawn from a tank under atmospheric pressure and is forced through an ejector at high velocity.- The suction side of the ejector is connected throu h a check valve to the return line, and t e entire flow of'air and water in this circulation water.

.line is induced by the high velocity of thc 'IL- The mixture of air and;

water is delivered to the circulation from which the air discharges to atmosphere.

Water accumulates in the tank until.sufii cient is present to open a' fioat operatedvalve, which permits either the circulation separate water pump to deliver the excess water to the boiler. The

Youngsystem is ty iccl of this mode'oioperation." One ob' ion to this 'stem is its extremely low e 'iency due to t e entire dependence upon the water operated ejectorand the large amount of water which must be- ,wastefully handled during normal operation.

give maximum air displacement,

and again the gas delivery ent system is built around the desired char-'- automaticall ables name y,

According to my invention, I depart from both of the prior modes of operation and secure a high efliciency of operation and relativel great-simplicity of apparatus by the empliayment ofa peculiar form of pump and controlling apparatus, such as I shall ,hereinafter describe.

'leak into the vacuum lines.

The pump, under a given set of conditions, will handle its maximum capacity of air discharge when a certain ratio of gas to 1i uid is supplied to the intake of the pump. hat is to say, if the ratio of gas to liquid in the intake of the pump, which I term herein the intake gas ratio, drops substantially below a predetermined livery' drops because too'much of the discharge is taken up by'liquid. On the other hand if the gasfratio istoo high, not enough liquid is present to entrainthe air required drops.

Now, the gas ratio is aifected in turnby the back. pressure. "If the head against which the pump must deliver its discharge is high, then the gas ratio should be lowered and .vice versa. p 7 1 Now, the theory of operation of my presacteristics of a proper gas ratio for the pump. That is to sa the present system is controiled by 'thekthree varithe'flow of gas and the flow of liquid.on the intake side pressure on the discharge. .The effect of 'back pressure upon the gas ratio is easily ratio for the pump.

f a supplementary comprehended in the compressibility of the nels.

gas and the incompressibility ofliquid.

The operations and stages of action are all designed to be performed at such times and in such manner as to providethe proper gas Incidentally, I employ at a certain stage of operation a gas e ector'to raise the rate active only as of gas discharge,*but this is device to extend the range of (gas delivery upon dropping the back pressure to atmosphere. Obviously, if the discharge pressureshould drop below intake,

pressure (and this actually does occur at one stage of operation),-the rate-ofgas delivery would be limited only by the size of the com nection. It is to take care of the special condition'of an excess of gas on the intake side and a low back pressure as a primary operating value which is found tov the gas deand the back' current of the discharge of the pump.

charged from the of the fluid mixture thatI employ-the intake. This is-done on ejector. The ejector is to. be regarded not ary or auxiliary device pensed with if desired.

The thing to be considered primarily is the action of'the pump and the ways it is utilized to meet the varying conditions of which could be disunit, but as a secondgas, liquid and back pressure above referred The pump is npt claimed herein but is claimed in my co-pending application, Serial No. 751,210, filed Nov. 21, 1924.

The procedure which I employ is briefly as follows: I utilize a chamber on the intake side which, under certain circumstances, serves as a liquid trap. I employ a large chamber on the discharge side WlllCl'hSBIVGS normally as a gas separator. So long as a proper working intake gas ratio prevails, the pum takes gas and liquid and discharges t e same'intothe discharge tank or separating trap, where the gas is liberated or separated and and the li uid boiler, bot under pressure. f now the intake gas ratio increases too much, I must do one of two things, orv both; namely, either increase the liquid intake to restore the gas vratio or drop the discharge pressure to a point corresponding to the prevailing gas ratio, or a combination of both. i

Now, it will be obvious that if the pump size were very great, then the absolute values of the gas ratio might vary considerably and the pump still be able to do its work, but in a system of this kind, economy of first cost and economy of operation must be carefully worked out. As I have above indicated, the device of my invention must satisfy three variables, and hence theioperationis relatively complex. To make thedevice automatic, I provide suitable controls which depend for'their operation upon the effect which the three variables have upon the pump. I

I provide the pump with a vane which divides the discharge opening into two chan- Into .each of these channels I set Pitot tubes facing against the outflow or Controlling valves are operated 111 accordance with the pressures prevailing in said Pitot tubes. Said .Pitot tubes are devices for measuring tlie impact of the liquid dispunip. The impact pressure is ameasure of the velocity and density flowing past them. By dividing the flow into two parts, I get a very sharp and positive definition of the discharge into two quantities, one of which immediately and shar 1y defines or mdicatee an undue increase 0 the gas ratios The valve controlled by it puts into operatior means'to correct it by adding liquid to tlu the theory that thr discharged to atmosphere separately discharged into the;

65 invention;'

increase 'in the gas ratio occurred thru a .deficlenc in the amount of liquid to make up the ull load or capacity of the pump,

but if the volume of gas is so great that at 5 the given discharge pressure the delivery or capacity of the pump is not great enough, to handle the entire volume that would be" made up by'adding the amount of liquid reqlixiired tomake up the proper gas ratio, then i3 pump discharges the excess and returns to normal discharge pressure and corre-. spondlng gas ratio. If the gas ratio 1s still wrong, the sequence of operations is repeated. k

The pump under normal conditions creates a certain difference in pressure between the, intake and the discharge thereof. When the discharge pressure 18 released, the

pump is at once able to pull harder on the intake and handle a greater volume of gas.

This intermittent action of higher and lower suction on the intake is a valuable feature of my invention as it will break an air lock such as often forms in a bend. of the pipe and which devices of the prior art are 1ncapable of breaking.

As above intimated, one of the Pitot tubes is sensitive to such an increase of gas ratio as can be corrected by addition of liquid,

assuming the delivery head to remain the same, and the other Pitot tube is sensitive to such an increase of the gas ratio as would, if corrected by addition of liquid, overload the pump, and it therefore does not try to correct the ratio, but instead drops the delivery head to a point where the. prevailing gas ratio. may be a proper ratio. Hence, I speak of the one Pitot tube beihg sensitive to conditions requiring more liquid to cor- 4 rect the gas ratio and the other as'being sensitive to excessive. delivery head for a high gas ratio. While I employ Pitot tubes as elements sensitive to excessive gas ratio and.

to excessive delivery head, it is to be un derstood that I do not intend to limit the invention to such 'specific means. These Pitot tubes are measuring devices for measuring certain physical variables corre-' sponding to the phenomena which influence.

5 operation.

, In order to acquaint those skilled in the J art with the manner of constructing and operating an embodiment of my invention, I shall now disclose a. particular system which I have constructed and operatedand which embodies the invention. In the accompanying drawings:-

Fig. 1 is a side elevational view of a pumpmg. and control system embodying the Fig. 2 is a plan view of the same;

Fig. 3 is a side elevation taken from the left side of Figs. 1. and 2;

Fig. 4 is a longitudinal vertical section through the pump;

Fig. 5 is a, horizontal section through: the stufling box and through the pump;

and

illustrating the general characteristics of the pump.

The tank 1 is divided into two compart-.

ments or chambers, the lower one 3 being the receiving tank or chamber and the upper one 2 being the discharge tank or chamber.

The tank -1 rests upon a suitable base 4' which may be connected to or independent of the pump and motor base 5, which .is placed adjacent thereto. The pump and motor base 5 provides a suitable mounting for the electric motor 6 and for the pump 7 and its connected parts. The. motor 6-is connected to the pump 7 through a flexible coupling 8. The base5 carries a pedestal supporting a suitable bearing 9 between the motor and the pump, and this pedestal 10 has an in- I Fig. 6 is a diagram of the connections;

Figs. 7 and 8 are explanatory diagrams tegral ring or support 11 for receiving a my co-pendm application, Serial No. 541,- p

030, above. re erred to, but it differs there from in certain important as 'cts which are employed herein as controls or determining the operation of the system. The .pump comprises the runner 15, which is mounted upon shaft 16. The runnerhas a series of peripheralpockets, as indicated at 17 in Fig. 4, formed upon opposite sides of a central flange or. ring 18, which ring is connected by spider arms 19 to the central hub 20. The pockets are formed as lateral recesses in the periphery of the pump runner. This pump runner fits relatively closely in a peripheral grooveor channel 21 formed in the pump casing. The pump casing is formed of a main back portion'22 and a cover member 23, said cover member '23 closing one side of the peripheral channel or recess which is formed in the main body member 22. The body member 22 and the cover 23 have cooperating flanges. 24 and 25 for bolting the two parts together, as by means of the bolt 26. The cover 23 has a conical inlet'with a lateral opening 27--surrounded by a suitable bolting flange 28'adapted to cooperate with a similiar pipe flange 29 for the inlet pipe 30. i

The gland which I have above referred Ian to isformed in the cylindrical boss 12 by' which the pump is mounted in the support 11. A. suitable counterbore 32 is formed in said boss 12 for receiving, packing material 33, which may be of the well known fibrous or other character. A gland or sleeve member 34 has a reduced end fitting into' the counterbore 32 to compress the packing 33 against the shaft 16. This sleeve 34 has, in turn, an enlarged outer end 35 which is recessed, as indicated at 36, to receive packin material about the shaft 16, and a suitab e gland 'member 37 is arranged to enter said counterbore36and compress the pack- Suitable wing nuts 44 are mounted on the bolts 43 for compressing 30 n will Imachined substantially flat,

not of, prime importance. The. passageway ing therein for forming a second seal about the shaft 16.- Between the two stufling' boxes and in the reduced portion of the sleeve member 34, I have provided a recess 38 which is adapted to be'filled with a suitable lubricating material, such as grease, as by means of a grease cup not shown connected to said space 38.

The gland 37 has across bar 38', the outer ends of which have slotted sockets, as indicated at 39 and 40, for receiving compression springs 41 and 42 which surround the gland bolts 43 and lie in said sockets 39 and 40.

the springs 40 to .ppt the stufling box and gland structure under suitable compression. square or noncylindrical heads '45 and are seated in suitable pockets or sockets 46, being thereby prevented from turning.

be apparent from the above 'de-' scription and from the drawings, particularly Fig. 5, that the bolts 43 may be very readily removed by compressing the sprmgs 41 and 42 and raising the heads 45 out of the sockets 46. Thereupon, the s'tuiiing box structure maybe disassembled by moving the parts to the left, as indicated in Fig. 5-;

Now, referring. to Fig. 4, I wish to call attention to the passageways and 51 which are formed in the pump, casing. These passageways are formed in 22 of the pump, so that the cover may be 50 is the discharge passageway for liquid and -gas from the pump to the separator 52. v a separator has .a flange 53 at the-bottom clamped to a flange 54 on the. casing sections of the pump, and an opening or passageway 55 is formed in the lower part of said separator 52 with a baflle 56 to throw the discharge from the pump to one sideto give thefluid discharged from thepump an opportunity to "separate out its gaseous con stituents from itsli'quid constituents. The

liquid tends to drop tion of the separator 'andgto pass out of the separator 52 throng passageway 58, whic passageway 51' in back into the lower por "communicates .w1

halves, the pee The bolts 43 have the main portion although. this is- This.

fluid in adownward 7 6. The :pipe 76 1s adapted "vapor from the top of discharged 52 into the open ng 57 p h charge into the th tank 2 through the "pump-,casing-T The fsbown, provided inthe upper tank.) to

lower end ofpassageway 51 terminates in a peripheral pocket in "each etl 5,9 in the casing half 22 being as shown in Fig. 4.

The pockets 59 extend a substantial distance radially along the pump runner, so as to'give a suitable o portunity for liquid descending through t e passageway 51 to fill the pump runner pockets 17, as they pass by the pockets 59. f

' The discharge passageway 50 terminates at its inner end in a peripheral opening 60, whichopeningexten s a substantial distance along the periphery of the .runner 15. This opening 60 provides a substantially tangential outlet for liquid from the pockets 17. Just beyond the opening a baflle or vane 61' for discharge.

60, I have provided stratifying the flow of On each .as it is discharged fromthe pump, so that a pressure will be caused in the Pitot tubes 62 and 63 bearing 'a certain relation to the velocity and inertia of fluid flowing out through the channels 64 and 65 0n opposite sides of the vane v In .opera ion, the amp is initially primed with suflicient'.-liqui to start operation, and with a priming charge such as may be secured by a trap in the intake,v the pump will liquid, in each case operate to pump gasor maintaining a ,positivesuctmn of relatively high value.

The pump, reference character 70, has its intake 30 connected to the lower or receiving tank 3 through two branches; namely,

point in the receiving tank 3 and abranch 72 which leads through an automatic pressure control valve 73 to the top or high level int in the receiving tank 3. This valve 73 is adapted to be automatically opened by spring pressure and closed by fluid vpressure, operating upon a fluid pressure element 74, said element being connected by a smalltube 75 with the Pitot tube opening 63 in the pump throat. The upper branch 72 which communica tank 3 contains a T-connectioii for pipe which leads to the ejector77, This pipe contains a check valve 78 to direction in said pipe the. tank a to'the 77, which ejector is'operated by' liquid through the pipe 79 from the ump 70. The ejector 77 is adaptedto disupper part of the discharge connection 80. .Abafiamot ejector of the casing 76. prevent flow of I to convey gas or which I shall designate by'the the branch '71 which leads to the bottom or low level with the top of the receiving system.

The discharge tank 2 has an upper air dischar e connection 83 which is controlled by a va ve 84 operated by float 85 Said discharge tank 2 also has a discharge connection 86 leading to the boiler for discharging water to the boiler through check valve 87.

Between the discharge connection 86 and the intake connection 82, I provide a bypass 88 controlled by a suitable valve 89.

This valve is constructed like the valve 73 and it has its pressure controlled element 90 for closing the valve against the spring which tends to hold it normally open. These automatic pressure control valves are articlesof commerce and well known in the art. The pressure element of the valve 89. is connected by means of a small tube 9l to the Pitot tube opening 62 in the throat of the pump.

The operation of the device is as follows: So long as the pump is provided with an adequate supply of water and an amount oiv gas which will result in a gas ratio at or below the desired maximum, the pump operates to discharge a mixture of gas and water out of the throat 60, which mixture impinges against the Pitot tubes .62 and 63 and creates sufficie'nt pressure in the tubes and 91, and in their connected pressure elements 74 and 90, to close the correspondin valves 73 and 89. Where the supply 0 the mixtureof gas and liquid is inadequate to fill the pump discharge; that is, when the gas ratio begins to increase beyond. a desired maximum, then the flow through the channel 64 and past the Pitot tube 62 will decrease, with the result that the pressure in said Pitot tube 62 will drop and the valve-90 will, under the influence of its sprin automatically open. The air which is eing discharged from the pump through the channel 64 will be separated out in the separator '52'and the liquid 'will run back through the opening 57, channel 58, passageway 51, 'into' the pockets 59, charging the water back into the pumping 'or runner pockets 1 7 in the runner 15.

If the supply of liquid to the pump'70. further decreases; that is, ifthe intake gas ratio is further increased, then there will be a further diminution in the impact pres sure of the mixture discharged 'throu 'h the channel 65, with the result. that the ow or impact pressure will not be maintained on the Pitot tube 63. The result is that such deficiency. of water to the pump will result in opening of the pressure control valve 73.

Now, with the above predetermined relations,"I

of the system. Assuming that steam is supand vapor which is created by the drop in pressure to rise to the top of the tank, and the liquid oes to the bottom or the tank and will, w iile the pump 70 is running, be drawn through the low level connection 71 into the intake 30 of the ump, which is placed at about the level oi the high level branch 72 which opens into thetop of'the tank 3.

Assuming that whilethe pump 70 is in operation a suitablequantity of liquid in proportion to the air is drawn in through the connection 82 from the radiators so that the gas ratio, that is, the ratio of gas to liquid, which arrives in the receiving tank 3 is within the normal working limitof the pump 70 for its proper efliciency, this mix-. tureof gas and liquid will be withdrawn from the tank 3 as it comes in from the pipe 82 and is dishar ed through the throat of the pump 70 t rough the receiver 52, pipe 79, past ejector 77, which is now inactive and through the connection into the discharge tank 2, where the liquid drops to the ttom and the gas is separated out upwardly. During normal operation, the

valve 8485 will be suflicientlyopened to throttle the discharge of air to maintain a suitable pressure upon the liquid to dnve it into the boiler. This condition will con-.

way'of the connection 86, check j and boiler feed pipe'86. Such The tendency in said tank 3 is for-the gas tinue during normal operation because i it will be seen that if the pressure of the by too large .an o ening of the valve 84, no liquid woul char ed b the pum le'veli of lipid and silmt olfthe 8 113. on top of the liquid should suddenly be discharged into the 1.5, boiler and the entering gasand'liquid 70'would..raise the So longas the pump 70 is operating upon fj,

normal gas ratio, the Pitot tubes 62 and 63 Wlll be great enough closed. v If, now, the gas ratio of the mixture mto the receiving tank 3 and into the pump 70 ressure 'upon the a to hold the respective valves 89 and. 73 i:

shall explain the normal operation increases to such a point where the impact 62 is insuflicient for mainpressure must be raised. Inthe present case,

. That is to say,

' "gas ratio values are plotted sure or di erence the the Pitot tube tamin the proper efliciency of the pump,

the va ve 89, which is a by-pass between the tanks 2 and 7 f3, will now be opened permitting liquid to flow rapidly from the tank 2 to the tank 3. The extent of opening of the valve 89 will correspond to the drop in pressure upon the Pitottube 62. The attempt made is to add suflicient liquid 'to the intake of the pump to'make' u for the incorrect as ratio; that is, to ma e up the" deficiency in liquid so that the pump may operate upona satisfactory etliciency. Now, it will be appreciated that this addition of liquid cannot continue indefinitel because to do so would be finally to over cad the pump. The pump has only a certain ca acity at a given delivery presbetween intake and discharge-pressure, and if the gas ratio cannot be corrected withinfthat delivery, then the delivery pressure must be dropped or intake the intake pressure cannot be satisfactorily changed because of the limitation of the vacuum' system, and hence I provide the means in the shape of the by-pass valve 7 3 and the float valve 84 to lower the discharge pressure of the pump 70 so that .av larger volume of mixture may be handled, and also so that a higher gas ratio .for such volume may be employed.

I have illustrated, by a diagram in Fig. 7, the general character of the operation of ump on difierences of pressure on the and discharge side of the pump. assume in the diagram of Fig. 7 that difierences in pressure between the intake and discharge side of the pump are plotted as abscissa and that the discharge as ordinates; then the varying ratio can be illustrated by a graph or curve which is somewhat of the character illustrated in Fig. 7. That is to say, as the pressure diflerence is increased, the amount of gas which can be handled inta e decreases rapidly, but as the. pressure diflerl is to say,

. ed the gas rratio,

through the pipe ence is lowered, the amount 0 gas which can be dischar ed is rapidly increased, and if the pressure ifierence becomes negative; that if an actual increase'in pressure in the intake over the discharge exists, then the amount of gas which can be handled that the opening of the e valve 89 has not correctthen the impact'pressure 'Pitot tube 63 drops to a Now, assumm by-pass through t measured on the point where the valve 73 opens and then temporarily the pump stops drawing h'quid through the pipe- 72. and the valve 73 has This opening of the by-pass 73 tempostream of liquid the oint of closing the atmo and the consequent gas ratio mounts very rapidly. the check valve 87 to the boiler.

sure is increase 71 because the a by-pass 1 large gas ratio upon iarily stops the operation of the pump 70 so far as pumping liquid is concerned, and it will contlnue for a time to discharge air onlyl orsubstantially hold delivery pressure wit out actually delivering any water to the tank 2. When the pumping of liquid stops, the liquid from the tank 2 flows through the valve 89 and begins to fill' the tank 3, dis-,

placing the air therefrom. The diiference in pressure between the tanks 2and 3 assists this flow. During the interval which inter venes between the -opening of and the raising of the liquid in the tank 3 to the level of the p-ipe72; that is, the intake of the pump 70, the pump delivers air only and the level of the liquid in thetank 2 lowers while air is being driven out of the atmospheric connection 83. When the level in the tank 2 lowers sufficiently to open the Valve 84, pressure in said tank 2 is dissipated by escape ofthe gases'to-atmosphere. The

pump 70 then has only .the atmospheric pressure to pump against,'and a resulting increase in volume of discharge occurs.

This intermittent higher and lower gas ratio is accompanied by correspondingly decreased and increased drafts of the pump upon the suction line or. the system. Such intermittent action is an important part of my invention because it will break an air lock which forms in certainparts of the pipe system. Suchair locks are often very diflicult to break by the devices of the prior art where such intermittent action is not provided.

As soon as the level of the intake'pipe the pump again takes up the liquid the tank 3 reaches the discharge of liquid, immediately increasing the pressure on Pitot tubes 62 and 63 and closing the valves '89 and 7 3 respectively. At this time, while the atmospheric connection 83 is open at the valve 84, thedischarge of a solid top of the tank 3, through the connection pipes 7 6, check valve 78 and out through the ejector 77, so that of gas is ejected due to discharge pressure. l

As soon as liquid'has filled the tank 2 to heric valve 84, t en the pressure in the ta 2i-ncreases to the point of. discharging liquid. through The ejector eration rapidly as the presand at normal operation; that is, when the normal gas ratio prevail's, the ejector 77 does not function. Thus it will'be seen that the ejector is. only an auxiliary apparatusv for securing a relatively large delivery of gas out of the tank 3iupon low delivery pressure of the pump.- It is such owering of the 77 goes out of'o of the pump 70,-

through the pipe 79\, and ejector 70 results in drawing air from the' the valve 73 v a relativel large amount thus a supplementary device for securing;

low pressure differences upon the terminals of the pump for extending the normal characteristics of the'pump itself.

The key to the entire operation is that of 'on the Pitot tubes 62 and 63. It will be seen that the normal impact pressure upon both of these tubes is substantially equal when the pump is pumping solid liquid; that is, when the intake gas ratio is zero. As the intake gas ratio increases, the pressure on the Pitot tube 62 drops more rapidly than the pressure on the Pitot tube 63, with the result that the valve 89 is opened ahead of the valve 73, as is apparent from the curves shown in Fig. 8. I do not mean to say that these curves show any absolute values, but merely the character of the relation.

. The'motor 6 which drives the pump 70 is controlled by a pressure sensitive element, so that when a predetermined drop in pres sure has been created on the return system, the motor is stopped and the pump thereby thrown out of operation until the pressure in the system has sufficiently raised or increased to require withdrawal of fluid from the'system.

liarity of the system illustrated Itwill be seen that there is, first of all, a straight passageway from the steam return line 82 through the apparatus to the boiler feed pipe 86 and if solid liquid were discharged from the radiators into pipe 82, this would be pumped through the system without any local circulation. Next, I call attention to the fact that if gas alone were dischargedthrough the auxiliary inlet 51.

Now, if the gas ratio be decreased, the internal circulation within the pumping unit will decrease. It stops substantially completely when normal gas ratio is reached. N ow, if however,'.the gas ratio increases after the ump has once been in normal operation,

the. y-pass 88 will open up, therebycreating the external circulation from the tank 2 to the tank 3 in an endeavor to keep up the gas ratio to avoid the local or internal pump circulation. Vhen the local or internal pump circulation occurs,the efiiciency of the pump is low and consequently the external or tank circulation is substituted, as it will maintaina higher over-all efiicieney of the pump and connected parts than if the pump had to rely upon its own local or internal circulation.

I do not intend to be limited to the details shown or described, nor to the specific rela- Now I wish to call attention to a pecutions which I have indicated. It will a thvious to those skilled in the-art. that the controls which I have shown as automatic may be secured manually within the spirit of my mvention, and it may be apparent to those skilled in the art-that the controls which I have illustrated may be applied to different specific apparatus. i i I claim:

- 1. In -a system ofthe class described having a pump for pumping a mixture of gas and liquid at a predetermined ratio, the method of maintaining said ratio which comprises measuring the impact pressure of the mixture discharged by the pump and adding liquid inversely in accordance with the impact pressure to maintain the same substantially constant.

2. In a system of the class described having a pump for pumping a mixture of gas and liquid at a predetermined ratio for a given difference between intake pressure and delivery pressure, the method of maintain ing the proper ratio which comprises measuring the gas ratio in terms of impact pres sure of the mixture discharged by the pump and lowering the discharge pressure upon a predetermined increase pf the gas ratio.

3. In a system havinga pump for pumping a mixture of gas and liquid at a predetel-mined ratio for a predetermined difference between intake and discharge of the pump, the method of maintaining the proper gas ratio which comprises measuring the impact pressure of the discharge of the pump, adding liquid to the intake of the pump as said impact pressure lowers, until the capacity of the-pump is reached.

4. In a system having a pump for pumping a mixture of gas and liquid at a predetermined ratio for predetermined diiference between intake and discharge of the pump,

the method of maintaining the proper gas ratio which comprises measuring the impact pressure of the discharge of the pump, adding liquid to the intake of the pump as said impact pressure lowers, until the capacity of the pump is reached, and then lowering the discharge pressure of the pump to. enable it to work on a higher gas ratio.

Ina system for pumping liquid with an admixture of gas, means for measuring the gas ratio of the mixture by its impact and means for correcting the gas ratio.

6. -In' a system of the class described, means for pumping a mixture of fluids from a given intake pressure to a predetermined discharge pressure. means for measuring the ratio of fluids pumped, auto matic means acting upon a hunted variation of said ratio to add a fluid to correct the take of the pumpi function of the impact head of discharge.

' intake of the pump, 10,

-'the back pressure upon pump, a vacuum system, connected to the ina discharge connection means for 0 ening the discharge to atmosphere when t e proportion of gas to liquid delivered 'to the pump exceeds a predetermined value: p

for the pump, an

8; In a system of the class described, a

ump, a vacuum system connected to the a discharge connection and means for decreasing the delivery side of the pump when the ratio of gas to liquid for the pump,

exceeds a predetermined head.

gle pump for drawing fluidsfrom the first,

tank and delivering them into the second 'tank, andmeans controlled bythe'inertia of the fluid discharge of the pump for controlling the discharge of the gas and for bypump for drawing paslsing liquids fromthe'second to the first tan r.

11.,In combination, a receiving tank, a connection'for receiving gas and liquid into the tank, a discharge .tank having separate gas .and liquid discharge connections, .a fluids from the first tank and deliveringthem into the second tank,- and fluid pressure operated means controlled by the level ofliquid in the first tank for controlling the gas ratio of the'fluid pumped fromthe said first \tank.

12. In combination, a receiving tank, a connectionfor receiving gas or liquid into the tank, a discharge tank having separate gas and liquid dischar e connect1ons a pump for drawing flui s from the first tank and delivering them into the second tank, a by-pas's from thesecond tank to the first tank, and fluid pressure operated means controlled by the level of liquid in the first tank for controlling said by-pass.-.

13. In combination, a tank for receiving gas and liquid, a pum havin its suction connected to the tank y one ranch at, a

- low level point andconnected-to the tank gas and liquid, a'centrifu by another branch at a high levelpomt, a valve for the hi it level connection and means controlled y} lowerin of the liquid to the low level connection or opening the high level connection to cause the pump to;

draw gas from-the tanks 14. In combination, atank for receiving al pump capable of pumping either gas or "quid andlhaving its suction connected to the tank by one branch at a low a level point and connected to the tank by another branch at a high level point, a valve for the high level connection and means controlled by lowerin of the liquid to the low level connection or opening the high level connection to cause the pump to draw gas from the tank.

15. In combination, a tank for receiving gas and liquid, a centrifugal pump pumping a normal mixture of gas and liquid from said tank, and means controlled by low level of liquid in the tank for causing the pump to pump a greater ratio of gas than normal.

.16. Inwxflnbiuation, a tank for receiving gas and liquid, a centrifugal pump capable of pumping a predetermined ratio of gas and liquid from said tank, means controlled by insuflicient flow of liquid into the tank for, causing areduction of the delivery pressure of the pump, and means controlled by high level of liquid in the" tank for causing the tank to pump a mixture of gas and liquid-having a gas ratio of greater value.

-'17.In combination, a tank for receiving gas and liquid, a centrifugal pump connected to the tank capable or pumping a mixture of gas and liquid against a predetermined delivery head, an ejector supplied with liquid by the discharge of.v liquid from the pump for drawing gas from the tank, said pumping the normal mixture of gas. and

ejector bei'n'gineffective when the pump is -liq'uid, and means controlled by diminution of the liquid discharged from the pump for lowering the discharge head of the pump to enable the ejector to draw gas.

Q18. In combination, a receiving tank adapted to be maintained under suction, a centrifugal pump capable mixture of gas and liquid connectedtosaid tank, an ejector'on the discharge side of said pump, said ejector having its suction connected to the top of said tank, said ejector being normally inoperative while the is pumping its normal ratio of gas and iquid of "pumping a l no at its normal delivery head, and means controlled by lowering of liquid level in the tank for putting said ejector into operation.

19. In combination, a receiving tank, a-

centrifugal pump capable of discharging liquid and gas, a receiving tank connected to the discharge oflsaid pump, separating means for separating gas from liquid in said discharge tank, and means controlled by insufiicient liquid in the receiving tank for causing the pressure and discharge a mixture .of and ii uid with a greater gas ratio.

20.- n combination, a receiving tank, a

centrifugal pump having its intake mountedat substantiallythe same level as the-upper part of said receiving tank, a connection I irom the upper part of the receiving tank .to the intake, a connection from the lower part of the receiving tankto the intake, a

pump to'drop its delivery gas I connection, a centrifugal pump having its intake mounted at substantially the level 21. In combination, a receiving tank hav-' ing a high level connection and a low level of the high level connection and being also connected to the low level connection, a valve in the high level connection, and'pres sure operated means controlled by discharge of liquid from the pump for closing the high level connection.

22. In combination, an upper tank having automatic air and water separating and discharging means, a receiving tank having a suction inlet, a valved by-pass between tanks, 2. pump having a suction connection into the lower tank and a discharge connection into the upper tank, and pressure operated means controlled by emptying of the lower tank of. liquid for opening the valved by pass.

23. In combination, a closed receiving tank, a pump capable of pumping gas and liquid, said pump being connected to the tank, means for delivering to the tank gas and liquid, a closed discharge tank, means controlled by lowering of the liquid level in the receiving tank below a predetermined value for open ng the discharge tank to atmosphere.

24. In combination, a closed receiving tank, a pump capable of pumping a mixture of gas and liquid, said pump being connected to the tank, means for delivering to the tank gas and liquid, means controlled by lowering of the liquid level below a predetermined value for causing the pump to lower ,its discharge pressure, and means controlled by rise of the liquid level to a prpdetermined point to cause the pump to pump a larger proportion. of gas and then raise its discharge pressure.

25. In combination, a closed receiving tank, a pump capable of pumping a mixture of gas and liquid, said pump being connected to the tank, means for delivering to the tank gas and liquid, auxiliary means comprising an ejector in the discharge of the pump for withdrawing gas from the top of the tank, said ejector being normally ineffective, and means to render said ejector effective when the proportion of gas to liquid discharged into the receiving tank is high.

in the discharge of thepump and having a suction connection to the top of the tank,-

and means for causing the pump to operate the ejector to draw gas from the tank only when the intake gas ratio in tank is higher than normal.

27. In combination, a receiving tank, a pump capable of pumping gas and liquid connected to said tank, an ejector connected in the discharge of the pump and having a suction connection to the-top of the tank, means controlled by an abnormally high gas ratio to provide a supplementary inflow of liquid, into the tank, and means controlled by continued abnormality of gas ratio for actuating the ejector to withdraw gas from thevtank.

28. In combination, a tank for receiving gas and liquid, a pump capable of pumping gas and liquid from said tank, an ejector in the discharge side of the pump for drawing gas from'the tank, and automatic means for lowering the discharge pressure of the pump tanks, a pump having a suction connection into the lower tank and a discharge connec-- the receiving so I tion into the upper tank, and pressure operated means controlled by emptying of the lower tank of liquid for opening the valved T by-pass.

30. In combination, an-upper tank and automatic air discharge connection and liquid discharge connection therefor, a lower tank, a suction line therefor, a by-pass between said tanks, a valve for said by-pass, a single pump capable of pumping either gas or liquid or both, said pump being connected between the lower tank and the upper tank, and automatic means controlled bythe character of the fluid discharge from the pump for controlling said by-pass.

31.In combination, an upper tank serving as a separator of liquid and gaseous fluids, means for automatically discharging gaseous fluid, means for automatically discharging liquid from said upper tank, a lower tank, a gravity by-pass between said tanks, a valve in said by-pass, a pump for pumping fluids from the lower tank and discharging them into the upper tank, and means governing the opening of the valve when the liquid in ihe }ower tank drops below a predetermined eve 32.In combination, a suction line,a,lower tank communicating with the line, an upper tank, a by-pass between the tanks, a pressure control valve in the by-pass, a rotary pump capable of pumping gas and liquid from the lower tank'to the upper tank, an outlet-for gas from the upper tank, a liquid discharge connection from the upper tank, and valve means controlled bythe discharge of liquid through the pump for closing said by-pass.

33. In combination, a pump' for pumping a mixture'ofgas and liquid at a predetermined .gas ratio and against-a predetermined delivery head, an intake system connected to theintake of the pump, a discharge system connected to the discharge of the pump, and means in the discharge of the pump sensitive to an excessive gas ratio for adding liquid to the intake system.

'connected to the discharge of the pump,

34. Incombination, a pump for pumping a mixture of gas and liquid at a predetermined gas ratio against a predetermined de-' mined gas ratio against a predetermined de-.

livery head, an intake system connected to the intake of the pump, a discharge system connected to the discharge of the pump, and means sensitive to an excessive gas ratio in' the intake for adding liquid to the intake system. I i 36. In combination, a pump for pumping a mixture of gas and liquid at a predetermined gas ratio against a predetermined deliveryhead, an intake system connected to the intake of the pump, a discharge system means sensitive to an excessive gas ratio of the intake for adding liquid to .the intake system, and means sensitive to a further increase in the gas ratio for dropping the pressure in the discharge system to permit, the pumping with a gas ratio higher than normal.

37. In combination a pump for pumping a mixture of gas and liquid'at a predeter- .mined gas ratio against a predeterminedvdelivery head, an intake system employin an intake trap connected tothe intake 0 the pump, a discharge system-employinga discharge trap connected to the discharge of the pump, means sensitive'to an excessive gas ratio for opening a: bypass between'the discharge trap-and the, intake trap for "adding liquid to the intake systemof the pump.

,38. In combination, a pump for pumping a mixture of gas andliquid at a predetermined gas ratio against a predetermined delivery head, an intake system employing an intake trapconnected'fto the intake of the pump, a discharge system employing a discharge trap connected to the discharge of' y the pump, means sensitive to an excessive gas ratio for opening arby-pass between-the discharge trap and the intake :tr'a'p -toadd liquid to the intake of the pump, and means sensitive to a further increase in the gas ratio for connecting the discharge tra with atmosphere to drop the pressure in t 1e discharge system to permit pumping with a gasratio higher than normal.

39. In a pumping system for a steam heating plant having a return line, the combination of a self priming pump having an in.- take connected to the return line and having a discharge connection, and means for controlling the back pressure inthe discharge connection to vary intermittently the sucr tion'upon, the intake connection.

. 40. In a pumping system for a steam heating plant having a boiler feed line and a' return line, a self priming )ump adapted to pump gas and liquid from the return line, a separator for separating gas and liquid connected to the discharge of the pump, said boiler feed line being connected to the separater for the discharge of liquid, and means for intermittently opening said separator to atmosphere to reduce the back pressure upon the pump and thereby intermittently increase the suction upon the return line.

41. In a pumping system for a steam heating plant having a boiler feed line and a return line, a.self priming pump adapted to pump gas and liquid tom the return line and discharge the liquid to said boiler feed line and means for intermittently bypassing the discharge of the pump to the intake and to atmosphere to increase the pumping of gas from the return line.

42. In a system for pumping liquid and gas, a pump, means responsive to decrease of delivery of the pump for sharply decontrolling the ratio of gas to liquid passing through the'pump, and means for decreasing the delivery pressure on the. pump and simultaneously increasing the suction upon the intake when the pump is called upon to deliver a higher gas ratio.

45. Inia heating system havin a return pipe, a gas and liquid pump and a oiler feed pipe connected to the discharge of the pump, the method of breaking an air lock in the return pipe which comprises temporarily releasing the discharge pressure upon the pump and thereby increasing the suction 'upon the return pipe.

46. Ina pumping system, a gas and liquid pump, a return lineconnected to the intake of'the pump a pressure discharge-line for the pump and meanscontrolled by the rate of delivery of the pump for releasing 'thedischarge pressure to increase the V pressure discharge line,

pumping of gas from the return line.

47. In combination, a steam return line, a centrifugal liquid and of creating a predetermined difference of pressure between'said lines and means for automatically releasing the pressure upon the discharge line to break an air lock in the steam return line.v

48. In combination, a steam return line, a a centrifugal liquid and air pump capable of creating a predetermined difference of pressure between said lines for a given delivery of liquid and gas at a given gas ratio and means for automatically increasing the gas ratio when the delivery drops off.

49. In combination, a steam return line, a pressure discharge line, a centrifugal liquid and gas pump capable of creating a predetermined difference of pressure between said lines for a given delivery of liquid and gas at a given gas ratio and means for automatically decreasing the delivery pressure when the delivery of the pump drops off.

50. In combination, a steam return line, a pressure discharge line, a centrifugal liquid and gas pump capable of creating a predetermined difference of pressure between said lines for a given delivery of liquid and gas at a given gas ratio and means for automatically increasing the delivery of the pump when the gas ratio decreases.

51. In a device of the class described, a single pump having an intake and a discharge connection, said pump being capable of pumping a predetermined delivery of both gas and liquid at a predetermined gas ratio at a predetermined difi'erence of pressure between intake and discharge, and means controlled by deviation of one of said predetermined conditions from normal for by-passh tank connected to the ing a part of the liquid from the connection to the intake. 4 k

52. In a device of the class described, a

discharge .pump having an intake and a discharge connection, said pump being capable of pumping a predetermined .delivery of gas and liquid at a predetermined gas ratio and at a predetermined difierence of pressure between intake and discharge, and means controlled by deviation of one of said predetermined conditions from normal for auto matically varying another condition to compensate for the deviation. I

53. In asystem of the class described, a return pipe, a boiler feed pipe, a centrifugal pump having an intake connected to the re turn pipeian impeller, a separating chamber connected to the discharge from the impeller and a return connection from the separating chamber to the impeller, a separating discharge of the separating chamber, a by-pass connection from the tank to the intake of the pump, means gas pump capable for automatically controlling said by-pass to maintain a suitable gas ratio through the pump, the return connection being active to return liquid to the impeller only when the gas ratio is excessive.

54. In combination, a suction pipe, a pressure delivery pipe, a centrifugal pump for pumping gas and liquid,-said pump having an impeller and an internal return circuit an auxiliary inlet for returning liquid from the separator to the impeller, a gas or liquid discharge connection leading from the top of said separator to the delivery pipe, a gas and liquid separating tank in said connection and an automatically controlled by-pass between the liquid space of the'separating a tank and the suction pipe.

55. In a system of the class described, a self priming pump having a suction pipe and a discharge pipe, a by-pass between said pipes, said pump having a divided'discharge throat and means governed by the pressure in one division of said throat for controlling said by-pass.

56. In a system of the class described, a self priming and a discharge pipe, a by-pass between said pipes, said pump having a'divided discharge throat and means governed by the pressure in one division of said throat for controlling said by-pass, means in the intake for accum- .ulating liquid and delivering only-gas to said pump, said means being controlled by the pressure in the other division of said throat. I,

57. In combination, an upper tank, a delivery pipeleading therefrom,-a lower tank, a return pipe leading thereto, a single pump having its suction connected to the lower tank and its discharge to the upper tank, a connection between the tanks, a valve therefor, and means controlled by the impact of the liquid delivered from the pump to control said valve.

58. In combination, a receiving tank for gas and liquid, a separating tank for separating gas and liquid a centrifugal pump between the tanks, said pump having its intake connected to the lower tank and its discharge connected to the upper tank,'a connection between said tanks, a valve controlling said connection, means controlled by the gas ratio of the fluid discharged by said'pump for operating said valve to permit liquid to flow from the'upper tank to the lower tank.

59. In combination, a receiving tank for receiving gas and liquid, a pump having a suction inlet connected to the receiving tank, a. separating tank for gas and liquid connected to the discharge of the pump, said separating tank being above the receiving tank, means to discharge liquid from the upper tank to the lower tank when the above the first tank,

pump having a suction pipe tive pumping action of the pump until the liquid in the lower tank reaches a predet'ermined level.

' 1 a vapor heating system an condensate to the boiler, which comprises 60. In combination, a receiving tank, a connection for receiving gas and liquid into the tank, a discharge tank havlng separate gas and liquid discharge connections, anda single centrifugal pump for drawing simultaneously under suction gas and liquld from the first tank and delivering them s1- multaneously under pressure into the second tank.

- 61. The method of withdrawing fluid from returning the creating a-flow of the condensate fromsaid hea-tmg system,,caus1ng said condensate to entrain uncondensable gas, discharglng the condensate and gas under pressure, separating the gas from the liquid under pressure, discharging a portion of the liquid under pressure to the boiler, and returning a portion sufiicient to maintain the flow substant'ially constant.

62. In combination, a receiving tank, a"

connection for deliverying gas and liquid into the tank, a discharge tank for receiving under pressure the entire discharge from the pump, said tank having separate gas and liquid discharge connections, and a single self-priming centrifugal pump for pumping gas or liquid or both under suction from the rst tank and delivering the same under pressure to thesecond tank.

63. In combinatiomia' steam returnline, a pressure discharge line, a single centrifugal liquid and gas pump capable of creating a predetermined difference of pressure between said lines for a given delivery of liquid and gas at a given gas ratio, and means for automatically by-passing' from theipump dischargeto the pump suction .a

ng a casing,

part of the liquid to increase the'total amount of gas delivered without proportionally increasing the total amount of liq uid delivered.

642- In combination, a centrifugal pump capable of pumping gas and liquid comprispassageway, a vane in the discharge passageway for stratifying'the fluid discharged by the impeller according to its density,

Pitot tubes disposed in said discharge passageway- Oll opposite sides of the vane, and

means responsive to the difference in pres-- sure upon said Pit-ct tubes for controlling theratio of gas and liquid admitted into the casing of the pump.

65,. In combination, a centrifugal pump capable of pumping gas and liquid in a predetermined ratio at a given pressure difference, means for supplyingv gas and liquid at a variable ratio to theintake of said pump, and means-sensitive to the gas ratio of the mixture pumped for controlling'said supplying means. i f

66. In combination, a centrifugal pump capable of pumping gas and liquid comprising a casing, a runner therein, a divided discharge passageway for stratifying the discharge of the pump according to density,

a Pitot tube in one of the divisions of said discharge passageway and means responsivev to the pressure on the Pi tot tube for measuring the gasratio of the discharge of the pump.

67. Incombinatlon, a centrifugal pump a runner therein, a discharge capable ofpumping gas and liquid compris ing a casing, a runner therein, a divided discharge passageway for stratlfying the discharge of the pump according to density, and means responsive to the difference inimpact pressure of the fluid in the divisions of said passageway for measuring the gas ratio of the discharge of the pump. 0

In-witness whereof, I hereunto subscribe my name .this 21st day of February, 1924.

HARRY E. LABOUR... 

